QCY T18 MeloBuds true wireless earbuds are a new generation of QCY products, and the appearance and texture have been further improved. The configuration is equipped with a new generation of Qualcomm QCC3050 chip, Bluetooth 5.2, supports Qualcomm Snapdragon Sound technology, supports aptX Adaptive audio decoding, and can provide 24-bit/96Khz wireless audio transmission. Support aptX Voice technology, 32kHz ultra-wideband voice quality, with Qualcomm cVc8.0 noise cancelling algorithm, presenting ultra-clear voice call effect.
52audio has previously dismantled QCY products including: QCY T17, QCY T11, QCY T10, QCY T13, QCY T1C, QCY T1, QCY T1S (wireless charging version), QCY T4 TWS, QCY T5, QCY T5S and QCY T6. Let’s take a look at the detailed teardown report of this product.
01/ QCY T18 MeloBuds charging case teardown
Through unboxing, we learned the detailed design of the QCY T18 true wireless earphones. Enter the teardown section below to see the internal structure configuration information.
Pry open the shell and take out the charging case cockpit structure.
There is an FPC cable on one side of the cockpit to connect the indicator light and the Hall element.
The battery is placed inside the cockpit structure, and a baffle is provided outside for fixed protection.
There are also FPC cables on the side of the cockpit, and function buttons on the top.
The motherboard is fixed to the bottom of the cockpit by screws, and the FPC cable and battery wires are welded on the motherboard.
Remove the screws and remove the main components in the charging case.
There are square magnets at the bottom of the cockpit, which are used to adsorb and fix the earbuds and charging case cover.
The main component circuits in the charging case.
Function keys for bluetooth pairing.
The LED and Hall element cables are connected to the motherboard through ZIF connectors.
The LED indicators on the cable are wrapped in black foam to prevent light leakage.
The hall element of the silk-screen ARPF1 is used to sense the magnetic field change when the charging case cover is opened/closed, and then notify the charging case MCU to control the earphones to pair or disconnect from the connected device.
Built-in lithium battery in charging case Model: PATL 901828, capacity: 380mAh/1.41Wh, voltage: 3.7V, from PATL.
The positive and negative electrodes of the battery are soldered to the wires. There is no independent protection board, and the protection circuit is located on the main board.
The circuit on one side of the charging case motherboard.
circuit on the other side of the motherboard.
The Pogo pin connector on the motherboard for charging the earbud.
Silkscreen 25BAC lithium battery protection IC.
LPS LP7801TE is an ultra-low power charging and boosting single chip, specially designed for charging/discharging of small-capacity lithium batteries. Integrated linear charge management module, low-power synchronous boost discharge management module, built-in power MOS, external programmable charging current, maximum charging current 1A, standby current of the entire earphone compartment <10uA when 5V is normally open (including earphones, protection plate).
LP7801TE adopts ESOP-8 package, and the switch pin adopts high-voltage 9V process, which can effectively absorb the high-voltage peak of production capacity when the earphone is plugged and unplugged, and at the same time, there is no whistling sound within the full load capacity range (especially light load). Built-in OVP, built-in NTC is precisely adjustable, the input withstand voltage is 28V, eliminating the need for input overvoltage protection components, and the standby current is 1uA. The boost module efficiency is as high as 95%, the switch pin has a high withstand voltage, a fixed 5.1V output, less peripherals, and less ripple.
According to 52audio, there are audio products from Black Shark, Xiaomi, Honor, OPPO, Huawei, Redmi, realme, Lenovo, Sony, Nokia, Motorola, Edifier, Soundcore, 1more, QCY, UGreen, Razer and many other brands. The product adopts LPS power management chip.
A non-standard MCU microcontroller, used for the whole machine control.
Type-C charging socket, through-hole welding and fixing.
02/ QCY T18 MeloBuds earbuds teardown
Enter the earbuds teardown section and pry open the cavity along the parting line. The speakers inside the front cavity are connected to the main board inside the earphone stem by wires. The battery unit inside the rear cavity is provided with a sponge pad for protection.
Take out the battery, and there is also a sponge pad isolation between the bottom and the motherboard.
The side of the cavity is used to attract and fix the magnet with the charging case.
At the bottom of the rear cavity, the wires for the speaker and the battery are soldered to the motherboard respectively.
Take out the speaker, the internal structure of the front cavity, and the openings are protected by a fine dust-proof net.
On the front of the speaker, the diaphragm is covered with a metal cover.
On the back of the speaker, there are tuning holes on the side, which are protected by a dust-proof net.
After actual measurement, the speaker size is about 10mm.
Pry open the earphone handle cover to reveal the internal structure of the cavity.
Take out the motherboard, inside the earphone handle cavity.
A touch detection patch and a bluetooth antenna are attached to the cavity wall.
The acoustic pickup structure of the call microphone is provided with a dust-proof net corresponding to the pickup hole of the microphone on the motherboard. There are two metal copper posts at the end of the earphone handle, which are connected to the motherboard connector to charge the earbud.
The circuit on the side of the earphone motherboard.
The circuit on the other side of the earphone motherboard.
The Qualcomm QCC3050 bluetooth Audio SoC is an ultra-low power, single-chip solution optimized for use with true wireless earbuds. QCC3050 supports Qualcomm Snapdragon Sound audio technology platform, including aptX Audio, aptX Voice, aptX Adaptive audio technology, Qualcomm cVc echo cancellation and noise suppression (ECNS) technology. Also supports adaptive active noise cancelling (ANC) technology, which is not used in this product.
Qualcomm QCC3050 adopts quad-core processor architecture, including dual-core 32-bit central processing unit, dual-core 120Mhz configurable Qualcomm Kalimba DSP audio subsystem, DSP has 112K program memory and 448K data memory. Bluetooth version 5.2, supports Qualcomm TrueWireless mirroring technology, supports bluetooth low energy consumption and dual-mode bluetooth the bluetooth rate is up to 3Mbps, and the power consumption is less than 5mA. Support mono output, using BGA package.
According to 52audio, there are many TWS true wireless earphones, over-ear headphones, neck hanging bluetooth headphones, smart speakers, smart audio glasses and other audio products that use Qualcomm bluetooth audio SoC.
The MEMS microphone of the laser carving IA205 is used for voice pickup.
The MEMS microphone of the laser engraving IA206 is beam-forming with the call microphone, which is used for the noise cancelling function of the call and provides a clear voice call effect.
A metal connector for charging the earbud by connecting the copper post inside the earphone stem.
Pogo pin connector to connect the bluetooth antenna.
Next to the connector connected to the touch detection patch is a touch detection IC with silkscreen “HH01F” for touch control function.
Two LED indicators of different colors are used to feedback the working status of the earbud.
The crystal oscillator of 32.000MHZ provides the clock for the bluetooth chip.
The periphery of the main control chip is equipped with two Scientic SDHL1608F4R7MT full magnetic shielding precision winding inductors. Inductance value: 4.7μH±20%, DC resistance: 700mΩ±10%, saturation current: 450mA, temperature rise current: 400mA, used to power the internal circuit of the bluetooth chip.
SDHL1608F4R7MT is one of SDHL1608 series. Adopt 0603 (Inch size) SMD package, with 1μH to 22μH standard gear sensitivity optional, small volume and high current, suitable for TWS bluetooth earphones, IoT devices, smart watches, smart bracelets, communication modules, facial recognition modules and other applications.
SDHL series precision wire wound inductors adopt a fully magnetic shielding structure to reduce radiation and interference to the surrounding area, and can optimize the noise floor and pop sound of TWS earphones. The copper wire is wrapped. In special cases, when the inductive whistle occurs, the wrapping layer can suppress the vibration of the copper wire, thereby optimizing the inductive whistling phenomenon.
The shielding layer of SDHL series precision wire wound inductors is made of materials with enhanced magnetic permeability, which enhances the performance of the inductors, and at the same time tightens the magnetic lines of force, so that the bottom of the inductors can be routed. There is no exposed copper wire at the bottom, which can avoid high-temperature solder paste sputtering in the process of patch production, thereby improving the quality control of batch products.
According to 52audio, TWS earbuds under brands such as OnePlus, QCY, Soundcore, MONSTER, etc. have adopted Scientific full magnetic shielding precision wire wound inductors.
iCM CM1126B-GAC 2-in-1 single-cell battery protection IC with shipping mode, built-in high-precision voltage detection circuit and delay circuit. By detecting the voltage and current of the battery, it can protect the battery from overcharge, overdischarge, and overcurrent. It is suitable for the protection circuit of single-cell Li-ion/Li-polymer rechargeable batteries, and also has a shipping mode, so that the small-capacity battery pack can meet the needs of maritime transportation and long-term storage.
The earbud has a built-in steel shell button battery, model: B467687032S, capacity: 45mAh/0.167Wh.
The inner motherboards of the left and right earbuds use different colors, which are easy to distinguish during production and assembly.
All components of QCY T18 MeloBuds true wireless earphones.
The QCY T18 charging case adopts a vertical oval design, which is similar to the piano paint process. The handle-shaped in-ear earbuds are combined with the curves and edges of the body, and the texture is matte and contrasting, which is highly recognizable.
In terms of internal circuits, the charging case uses the Type-C interface input power supply and has a built-in PATL 380mAh battery. The lithium battery protection is set on the motherboard, and the LPS LP7801T is responsible for charge and discharge management. It has a built-in power MOS, and the charging current is externally programmable. The maximum charging current is 1A. Built-in OVP, built-in NTC is precisely adjustable, and the input withstand voltage is 36V, saving input overvoltage protection components. A non-standard MCU microcontroller is also used for overall control.
The earbuds are equipped with a 10mm dynamic driver and a 45mAh steel-shell button battery, which are connected to the motherboard through wires. The motherboard adopts Qualcomm QCC3050 ultra-low power bluetooth audio SoC, supports Snapdragon Sound audio technology, supports aptX Adaptive audio decoding, and provides high-definition wireless audio experience. Support Qualcomm cVc echo cancellation and noise suppression technology, with two MEMS microphones, to achieve clear voice calls.